Cannot start the app in Windows 10

I have just installed CatLight 2.10.3 on a Windows 10 machine, but it won't run. The gears spin for a minute or two, and then the screen says "cannot start the app".

I tried installing the CRT but the installer said that it wasn't applicable to my version of windows.

I have attached the log files.


2 replies


Thanks for the response. It was a firewall issue as you suggested.

I got it working by running Windows Firewall with Advanced Security and setting up Outbound Rules for

  • C:\Users\...\AppData\Local\CatLight\app-2.10.3\CatLight.exe
  • C:\Users\...\AppData\Local\CatLight\app-2.10.3\resources\LocalWeb\LocalWeb.exe

Inbound Rules weren't necessary.


Hi Dean,

CatLight app has two parts - UI and a background service that does the actual monitoring. In your case UI part cannot connect to the background service. This can happen if there is an overactive firewall that blocks local TCP connections. You can add both parts (CatLight.exe and LocalWeb.exe) to the exceptions to allow such connections.